University Researchers - NEW
Edith Allen - Plant Ecology, Plant Sciences
Mike Allen - Plant Pathology, Soil Microbiology, Ecology
Dennis Baldocchi - Biometeorology
Roger Bales - Hydrology, Glaciology
Carol Anne Blanchette - Intertidal Ecology
Elliott Campbell - Environmental Science, Engineering, Sustainable Energy, Bio Fuels
Yihsu Chen - Environomental Policy
Exequiel Ezcurra - Plant Sciences, Seabird Ecology, Oceanography
Sarah Feakins - Geochemical Analysis, Ecological Signals
Tessa Hill – Geochemistry, Geology
Darrel Jenerette - Landscape Ecology
Matthew E. Kirby – Paleoclimatology
Lisa Levin - Ecology
Mark Ohman – Ecology, California Current
John Rotenberry - Biology, Species Distribution
Louis Santiago - Physiological Ecology, Botany
James Sickman - Hydrology, Permafrost
Charles Zender - Climatology, Aerosols
Affiliation: Department of Botany and Plant Sciences, U.C. Riverside
- Study the ecosystem impacts of anthropogenic N deposition. This is indirectly related to climate change in that CO2 emissions, the main cause of climate change, co-occur with oxidized N emissions from automobiles. Agriculture is a major source of reduced N as well as another climate-altering gas, methane.
- This has shown that increased N causes increases in dominance of invasive exotic grasses in deserts and Mediterranean-type vegetation in California. As biomass of exotic grasses increases, vegetation that has historically burned infrequently burns more often. Native plant species can no longer reestablish under this fire regime, and the vegetation converts from species-rich shrubland to exotic annual grassland.
Fenn, M.E., Baron, J. S., Allen, E.B., Rueth, H. M., Nydick, K. R., Geiser, L, Bowman, W. D., Sickman, J. O., Meixner, T., and Johnson, D. W. 2003. Ecological effects of nitrogen deposition in the Western United States. Bioscience 53:404-420.
Sirulnik, A.G., E.B. Allen, T. Meixner, M.E. Fenn, M.F. Allen. 2007. Impacts of anthropogenic N additions on nitrogen mineralization from plant litter in exotic annual grasslands. Soil Biology and Biochemistry 39:24-32.
Rao, L. E., D. R. Parker, A. Bytnerowicz, and E. B. Allen. 2009. Nitrogen mineralization across an atmospheric nitrogen deposition gradient in southern California deserts. Journal of Arid Environments, in press.
Affiliation: Departments of Plant Pathology and Microbiology, Biology, and Center for Conservation Biology, U.C. Riverside
- Understanding the responses of soil organisms to global change
- How do soil organisms affect soil-atmosphere carbon exchange rates
Vargas, R. and M.F. Allen. 2008. Dynamics of fine root, fungal rhizomorphs and soil respiration in a mixed temperate forest: Integrating sensors and observations. Vadose Zone Journal 7: 1055-1064.
Allen, M.F., R. Vargas, E. Graham, W Swenson, M. Hamilton, M. Taggart, T.C. Harmon, A Rat’ko, P Rundel, B. Fulkerson, and D. Estrin. 2007. Soil sensor technology: Life within a pixel. BioScience 57: 859-867.
- Measure and model carbon dioxide, water vapor, methane and energy exchange between vegetation (oak woodlands, annual grasslands, peatland pastures) and the atmosphere
- Trends in agricultural climate statistics
- Quantifying and Understanding Interannual Variability of Carbon, Water and Energy Exchange of an Oak Savanna and an Annual Grassland Ecosystem AmeriFlux Site .
- Understanding the Coupling of Greenhouse Gases (Methane, Carbon Dioxide, Water Vapor) and Energy Fluxes and Scaling them across a Spectrum of Time and Space over a Vulnerable Ecosystem and a Biological Hot Spot: the Sacramento-San Joaquin Delta Peatland
- Fluxnet, A global network of carbon, water, and energy flux measurement sites.
Baldocchi, D.D ., Wong, S. 2008. Accumulated winter chill is decreasing in the fruit growing regions of California. Climatic Change. 87, S153-S166 .
Baldocchi, D.D . 2008. ‘Breathing’ of the Terrestrial Biosphere: Lessons Learned from a Global Network of Carbon Dioxide Flux Measurement Systems. Australian Journal of Botany. 56, 1-26.
Ryu, Y. #, Baldocchi, D.D.,Ma, S., and Hehn, T. 2008. Interannual variability of evapotranspiration and energy exchange over an annual grassland in California. Journal of Geophysical Research, Atmospheres. 113, D09104, doi:10.1029/2007JD009263
Ma, S.*, Baldocchi, DD., Xu. L*, Hehn, T. 2007. Interannual variability in carbon exchange of an oak/grass savanna and an annual grassland in California. Agricultural and Forest Meteorology. 147, 157-171.
Affiliation: Sierra Nevada Research Institute and School of Engineering
mountain hydrology and climate
adaptive management of Sierra Nevada forests with regard to water
climate change and water resources
polar glaciology and atmospheric chemistry
Southern Sierra Critical Zone Observatory
Sierra Nevada Adaptive Management Project
Summit Greenland Environmental Observatory
Atmospheric, snow and firn chemistry studies for interpretation of WAIS-divide cores
Roger C. Bales, Dayong Shen, Guoming Du, Qinghua Guo, Joseph R. McConnell, John Burkhart, Vandy B. Spikes, Edward Hanna, John Cappelen. Annual accumulation for Greenland updated using ice core data developed during 2000-2006 and analysis of daily coastal meteorological data. Journal of Geophysical Research, Atmospheres, 114, D06116, doi:10.1029/2008JD011208 , 2009.
S.A. Anderson, R.C. Bales, C.J. Duffy. Critical Zone Observatories: Building a network to advance interdisciplinary study of Earth surface processes. Mineralogical Magazine, 72(1), pp 7-10, 2008.
Bales, R. C., N. P. Molotch, T. H. Painter, M.D. Dettinger, R. Rice, and J. Dozier. Mountain hydrology of the western United States. Water Resources Research, W08432, doi:10.1029/2005WR004387, 2006.
Bales, R. C., D. M. Liverman and B. J. Morehouse. Integrated Assessment as a Step Toward Reducing Climate Vulnerability in the Southwestern United States. American Meteorological Society, 85 (11): 1727, 2004.
Molotch, N. P., T. H. Painter, R. C. Bales and J. Dozier. Incorporating Remotely-Sensed Snow Albedo into a Spatially-distributed Snowmelt Model. Geophysical Research Letters, 31(3): Art. No. L03501, 2004
Affiliation: Marine Science Institute, U.C. Santa Barbara
- Intertidal ecology – species interactions, larval dispersal, community ecology
- Climate change effects in intertidal and nearshore marine ecosystems
- Ecology of marine plants – seaweeds and seagrasses
- Oceanographic effects on nearshore ecosystems – waves, upwelling, climate cycles
1. Climate Change and Thermal Stress
Temperature is critically important to nearly all physiological processes and holds great ecological relevance in governing the geographic distribution of species. Although air and water temperatures can be easily measured, these metrics have been shown to be uncorrelated with organism body temperatures, particularly for ecothermic organisms, whose body temperatures are influenced by multiple climatic drivers. Despite the great physiological and ecological importance of temperature, we know surprisingly little about the body temperatures of most organisms under natural conditions. This knowledge is becoming extremely important in the face of future global climate change. Predicted changes in temperature under projected climate change scenarios underscore the need to increase our understanding of how climate affects organism body temperatures and critical biological functions. Furthermore, we currently lack a mechanistic understanding of how climate-driven effects at the scale of individual organisms cascade into ecological processes that may regulate a species’ distribution. Thus, to predict ecological responses to climate change, we must forecast how organismal responses to temperature vary in space and time across trophic levels and among interacting species. Our work (B. Helmuth and B. Broitman – collaborators) has focused on understanding how organismal body temperatures in several selected species of invertebrates (mussels, seastars and abalone) are influenced by aquatic and aerial climate and how their populations may respond to predicted climate change scenarios.
2. Ecological Forecasting
Most ecological approaches to climate change research to date have quantified the effects of weather and climate on natural communities after these effects have been manifest. One major challenge before the scientific community, however, is to quantitatively forecast where and when such effects are most likely (and least likely) to occur so that scientists can work in collaboration with resource managers to reduce damage. The science of ecological forecasting applies principles of ecology, physiology and mathematical modeling to predict where climate change is likely to impact key species. As part of this project we (B. Helmuth, S. Navarrete, D. Wethey, S. Place and B. Broitman – collaborators) are investigating the effects of changes in temperature within the context of larval dispersal as they impact geographic patterns of ecologically and commercially important species along the north-central coast of Chile, and the central coast of California
3. Climate Change and Biogeography
A very basic prediction of most climate change scenarios is that species distributions will shift poleward as temperatures warm and equatorial thermal tolerances are exceeded. Because they are assumed to live very close to their thermal tolerance limits, organisms inhabiting the rocky intertidal zone have emerged in recent years as potential early harbingers of the effects of climate change on species distributional patterns in nature. We have recently found that because of the coupled effects of the timing of aerial exposure with terrestrial climate, latitudinal patterns of thermal stress are not only highly complex in space, but also in time. Under this scenario, increasing thermal stress will result in localized extinction hot spots and not in a gradual gradient of stress from south to north. We are further exploring the ecological and physiological ramifications of this idea for a variety of intertidal species and examining how their patterns of vertical distributions along a large-scale geographic gradient. Recently we've also found that latitudinal patterns of thermal stress in intertidal organisms are a 'mosaic', and unpredictable based on latitude alone.
Helmuth, Brian, Chris Harley, Patti Halpin, Michael O'Donnell, Gretchen E. Hofmann, and Carol Blanchette. 2002. Climate change and latitudinal patterns of intertidal thermal stress: Is life always hotter, south of the border? Science 298:1015-1017
Blanchette, Carol A., Daniel V. Richards, John M. Engle, Bernardo R. Broitman, Steven D. Gaines. 2005. Proceedings of the California Islands Symposium. Vol.6:435-441. Regime Shifts, Community Change and Population Booms of Keystone Predators at the Channel Islands
Helmuth, Brian, Bernardo Broitman, Carol Blanchette, Sarah Gilman, Patricia Halpin, Chris Harley Michael O'Donnell, Gretchen E. Hofmann, Bruce Menge and Denise Strickland. 2006. Mosaic patterns of thermal stress in the rocky intertidal zone: Implications for climate change Ecological Monographs 76(4):461-479
Broitman, B.R., L. Szathmary, K.A.S. Mislan, C.A. Blanchette, and B. Helmuth. 2009. Predator-prey interactions under climate change: the importance of habitat vs.body temperature Oikos 118:219-224
Blanchette, C.A., P.T. Raimondi, and B.R. Broitman. In Press. Spatial patterns of intertidal community structure across the California Channel Islands and links to ocean temperature Proceedings of the California Islands Symposium
Name & Title: Elliott Campbell, Assistant Professor,
Affiliation: College of Engineering & Sierra Nevada Research Institute, U.C. Merced
Research Overview: Elliott Campbell works in the area of environmental science and engineering focused on sustainable energy production. His current research falls in the interdisciplinary area of understanding the domain for sustainable biofuels with a focus on the interaction of ecological and human energy systems. To explore these topics, Campbell's group leverages a combination of ecosystem models, atmospheric transport simulations, GIS, data assimilation, and life cycle assessment.
- Optimal Bioenergy Pathways for Climate and Transportation Goals: Life cycle assessment is used to consider the net climate forcing and useful energy outputs for a range of bioenergy conversion pathways. This approach is particularly useful for considering bioenergy approaches that could offset future and historic climate forcing.
- What is the Potential of Marginal Agriculture Lands as a Bioenergy Resource?: Marginal agriculture lands may provide a sustainable domain for producing biomass that avoids some of the problems with the current trajectory of biofuels development. We are exploring the available area of marginal lands and the potential yields on these lands with land use analysis, ecosystem modeling, and field trials.
- Atmospheric Tracers for Biomass Yields and Carbon-Climate Feedbacks: The uptake of atmospheric carbonyl sulfide (COS) by plants suggests that COS gas can be used as a tracer of terrestrial photosynthesis. Data assimilation techniques using atmospheric COS measurements and models can be used to provide a new way to measure primary production and explore the feedbacks between the carbon cycle and climate change.
- Including Ecological Impacts in the Life Cycle Assessment of “Clean Coal” and Mountain-top Removal: The capture and sequestration of CO2 emissions at coal fired power plants may help to mitigate anthropogenic climate forcing. However, most studies overlook the large emissions of greenhouse gases that can result from terrestrial carbon pools during surface mining such as mountain-top removal. An ecological analysis of coal mining impacts can improve our understanding of the life cycle impacts of coal-based energy.
Campbell, J. E., Lobell, D. B., Field, C. B. (In Press) Greater transportation energy and GHG offsets from bioelectricity than ethanol, Science.
Campbell, J. E., Carmichael, G.R., Chai, T., Mena-Carrasco, M., Tang, Y., Blake, D.R., Blake, N.J., Vay, S.A., Collatz, G.J., Baker, I., Berry, J.A., Montzka, S.A., Sweeney, C., Schnoor, J.L., Stanier, C.O. (2008), Photosynthetic control of atmospheric carbonyl sulfide during the growing
Season. Science. 322: 1085-1088.
Campbell, J. E., Lobell, D. B., Genova, R. C., Field, C. B. 2008. The global potential of bioenergy on abandoned agriculture lands, Environmental Science and Technology: DOI: 10.1021/es800052w.
Field, C. B., Campbell, J. E., Lobell, D. B. 2008. Biomass energy: the scale of the potential resource. Trends in Ecology & Evolution. 23(2): 65-72.
Blake, N.J., Campbell, J. E., Vay, S. A., Fuelberg, H. E., Huey, L. G., Sachse, G., Meinardi, S., Rowland, F. S., Blake, D. R. (2008), Carbonyl sulfide (OCS): Large scale distributions over North America during INTEX-NA and relationship to CO2. Journal of Geophysical Research-Atmospheres, 113, D09S90, doi:10.1029/2007JD009163.
Campbell, J. E., Moen, J. C., Ney, R. A. Schnoor, J. L. (2008), Comparison of regression coefficient and GIS-based methodologies for regional estimates of forest soil carbon stocks, Environmental Pollution, 152(2), 267-273.
Name & Title: Yihsu Chen, Assistant Professor
Affiliation: Sierra Nevada Research Institute, School of Engineering, School of Social Sciences, Humanities and Arts, University of California, Merced
The Energy & Environmental Economics and Policy Analysis at UC Merced focuses on studying the interactions of environmental policies and industry activities. The recent focus is on the examination of economic and emissions impacts of the proposed California emissions trading programs.
- "Economic and Emissions Implications of Load-Based, Source-based and First-seller Emissions Trading Programs under California AB32" (with Andrew Liu and Benjamin F. Hobbs) : This study examined the economic and emissions implications of proposed emissions trading programs under the California's AB32. Computable economic spatial power market models were developed to analyze how might the market react under source-, load-based and first-seller approaches considered by the California Air Resources Board and California Public Utility Commissions. Full report can be found at http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1045&context=ucei
- "Regulation, Allocation, and Leakage in Cap-and-Trade Markets for CO2" (with Jim Bushnell): in this study, we estimated the magnitude of carbon leakage under various levels of regulation coverage and allowance allocation schemes in the western US. The results indicate California only program could yield substantial carbon leakage to other neighboring states. Updated-based allowances allocations can effectively ease the price impact on the consumers. Full report can be found at: http://repositories.cdlib.org/ucei/csem/CSEMWP-183/
- "Mapping California Solar Irradiance and Its Implications for Power Sector" (with Qinghua Guo and Carlos F.M. Coimbra) : in this ongoing project, we develop the protocol for mapping real-time California's solar potential using Geographical Information System technique. We then examine its economic (e.g., fuel and capital cost) and emissions implications (e.g., NOx, SO2 and CO2) under different levels of solar penetration.
Affiliation: UCMexus and Department of Botany and Plant Sciences U.C. Riverside
- The cycles of boom and bust in seabird nesting and sardine fisheries in the Midriff Region of the Gulf of California, and how these cycles relate to oscillations in ocean temperature and long-term ocean warming.
- The environmental services provided by mangroves, and how sea-level rise is affecting these services, especially the ability of the coastal wetlands to buffer the impact of tropical storms and to serve as hatching and feeding habitat for open sea fisheries.
- The impact of sea-surface temperatures on the intensity of Pacific frontal storms in winter, of continental monsoon storms in summer, and of tropical hurricanes in fall; and how future oceanographic anomalies may drive cycles of drought in land.
Velarde, E., D.W. Anderson, and E. Ezcurra. 2009. Comparative diet analysis of three seabird species in the Midriff Island region of the Gulf of California in relation to commercial small pelagic fisheries. Studies in Avian Biology (in press)
Peters, E.M., C. Martorell, and E. Ezcurra. 2009. The adaptive value of cued seed dispersal in desert plants. American Journal of Botany 96(2): 537–541.
Vieyra, L., E. Velarde, and E. Ezcurra. 2008. Effects of parental age and availability of small pelagic fish on the reproductive success of Heermann's Gulls in the Gulf of California. Ecology 90(4): 1084–1094.
Aburto-Oropeza, O., E. Ezcurra, G. Danemann, V. Valdez, J. Murray, and E. Sala. 2008. Mangroves in the Gulf of California increase fishery yields. Proceedings of the National Academy of Sciences 105(30): 10456–10459.
Caso, M., C. González-Abraham, and E. Ezcurra. 2007. Divergent ecological effects of oceanographic anomalies on terrestrial ecosystems of the Mexican Pacific coast. Proceedings of the National Academy of Sciences 104(25): 10530–10535.
Velarde, E., E. Ezcurra, M.A. Cisneros-Mata, and Miguel F. Lavín. 2004. Seabird ecology, El Niño anomalies, and prediction of sardine fisheries in the Gulf of California. Ecological Applications 14(2): 607–615.
Velarde, E., and E. Ezcurra. 2002. Breeding dynamics of Heermann’s Gulls. In: T. Case, M. Cody, and E. Ezcurra (eds.) A New Island Biogeography of the Sea of Cortés. Oxford University Press, Oxford, U.K. pp. 313–325.
Affiliation: Earth Sciences, University of Southern California
- Use of hydrogen isotopic composition of water and plant leaf waxes to assess past and present water usage and climatic signatures.
- When these tools are applied to leaf waxes and other biomarkers in lake sediments and ocean sediments we can gain important information about past climate variability.
- Understanding past patterns of wet and dry cycles in California are key to predicting future changes in the water budget, in this water-limited region.
- Characterizing the isotopic composition and water use regimes of modern vegetation from the coast to the inland deserts is a vital foundation for this research.
- Variations in the D/H ratios of plant leaf waxes from arid ecosystems (southern California).
- Biomarker isotopic signals of ecological responses to environmental change, at the Carpinteria Salt Marsh Reserve, Santa Barbara County, California.
Feakins, S.J., Eglinton, T.I. and deMenocal, P.B., (2007) A comparison of biomarker records of northeast African vegetation from lacustrine and marine sediments ca. 3.40 Ma, Organic Geochemistry, doi: 10.1016/j.orggeochem.2007.06.008.
Feakins, S.J., Brown, F.H., and deMenocal, P.B., (2007) Plio-Pleistocene Microtephra in DSDP Site 231, Gulf of Aden, Journal of African Earth Sciences, doi: 10.1016/j.jafrearsci.2007.05.004.
Feakins, S.J., deMenocal, P,B. Eglinton, T.I, (2005) Biomarker Records of Late Neogene changes in northeast African Vegetation, Geology, 33, 977-980.
- Research in the Hill lab focuses on recent marine environmental change, utilizing the geochemistry of microfossils and corals to determine rates and magnitude of climate change, the response and adaptation of species to environmental change, and the impact of ocean acidification on marine ecosystems.
- Much of this research focuses on synergistic impacts of climate change, including species abundance shifts, carbon cycling, oxygenation, ocean circulation, and the carbonate system.
- Stable isotopes (Ο,Χ,N), trace elements (Mg/Ca, Sr/Ca), radiocarbon, and foraminiferal species assemblages are used as proxies for temperature and geochemical changes.
- Bamboo corals as records of climate change in the ocean's interior
- Past and present pH variability in Coastal California: Impacts of anthropogenic ocean acidification
- Records of anthropogenic climate change from coastal environments
- Extending the Santa Barbara Basin climate record back to 1 Million years ago
- Methane hydrates: Interaction between natural methane seepage and climate change
Hill, T.M., Kennett, J.P., Spero, H.J. (2003). Foraminifera as indicators of methane rich environments: A study of modern methane seeps in Santa Barbara Channel, California. Marine Micropaleontology, v. 49, p. 123-138.
Hill, T.M., Kennett, J.P., Spero, H.J. (2004). High-resolution records of methane hydrate dissociation: ODP Site 893, Santa Barbara Basin. Earth & Planetary Science Letters, v.223 (1-2), p. 127-140.
Hill, T.M., Kennett, J.P., Valentine D.L. (2004). Isotopic evidence of methane-derived carbon into living foraminifera from modern methane seeps, Hydrate Ridge, OR. Geochimica et Cosmochimica Acta, v. 68 (22), p. 4619-4627.
Hopkins, S., Kennett, J., Nicholson, C., Pak, D., Sorlien, C., Behl, R., Normark, W., Sliter, R., Hill, T., Schimmelmann, A., Cannariato, K. (2006). Santa Barbara Basin study extends global climate record. EOS Transactions, American Geophysical Union, v. 87 (21) p. 205,208.
Hill, T.M., Kennett, J.P., Pak, D.K, Behl. R.J., Robert, C., Beaufort, L. (2006). Pre-Bolling warming in Santa Barbara Basin, California: Surface and intermediate water records of early deglacial warmth. Quaternary Science Reviews. V. 25 (21-22), p. 2835-2845.
Hill, T.M., Kennett, J.P, Valentine, D.L., Yang, Z., Reddy, C., Nelson, R., Behl, R. J. Robert, C., Beaufort, L. (2006). Climatically driven emissions of hydrocarbons from marine sediments during deglaciation. Proceedings of the National Academy of Sciences. , v. 103 (37), p. 13570-13574.
Keller, E.A., Duffy, M., Eichhubl, P.E., Kennett, J.P., Hill, T.M., Kamerling, M.J. (2007). Tectonic geomorphology and hydrocarbon induced topography of the Mid-Channel Anticline, Santa Barbara Basin, CA. Geomorphology, v. 89 (3-4), p. 274-286.
Paull, C.K., Ussler III, W., Holbrook, W.S., Hill, T., Keaten, R., Mienert, J., Halflidison, H., Johnson, J. Winters, W., Lorenson, T. (2007). Origin of pockmarks and chimney structures on the flanks of the Storegga Slide. Geo-Marine Letters, v. 28 (1), p. 43-51.
Affiliation: Department of Botany and Plant Sciences, U.C. Riverside
- Terrestrial carbon balance dynamics following changing precipitation regimes
- Urban ecological responses to altered temperature and water availability
Jenerette GD, RL Scott, and TE Huxman. 2008. Whole ecosystem metabolic pulses following precipitation events. Functional Ecology 22:924-930.
Jenerette GD and L Larsen. 2006. A global perspective on changing sustainable urban water supplies. Global and Planetary Change 50:202-211.
Affiliation: Department of Geological Sciences, CSU Fullerton
- Study water resource management issues from a historic (past 200 years) and pre-historic (last glacial-interglacial cycle) perspective;
- Use the physical, chemical, and biological components of lake sediments to reconstruct the history of general climate variability, droughts, floods, and fire behavior;
- Focus almost exclusively on the over-populated and water-poor region of Southern California;
- The purpose of this research is to provide a baseline knowledge of past climate variability and its associated phenomena (i.e., droughts, floods, fires) as a template for assessing recent and future climate change and its impact on water resource management issues.
- A Combined Geophysical and Lithostratigraphic Investigation of a Young Pull-Apart Basin: Evaluating the Relationship Between Basin Sedimentation, Late-Quaternary Climate Change, and Tectonics (Lake Elsinore, Southern California)
- Assessing Multi-scale Holocene Climate Variability in Western North America Using Sediments From Lake Elsinore (Southern CA)
- Developing Late-Holocene Records of Flood-Producing Precipitation Variability From Small Lakes in Southern California
- Understanding Holocene Climate Change From an Alpine Lake in Southern California (Dry Lake, San Bernardino Mtns.)
- An Investigation of Holocene Wet-Dry Cycles in Southern California as Recorded in Ancestral Big Bear Lake
- Geophysical Exploration of Small Catchment Alpine Lakes and Their Paleohydrological Significance
2009 Blazevic, M.A., Kirby, M.E., Woods, A.D., Browne, B.L., Bowman, D.D., Facies Model For Glacial-Age Sediments, Baldwin Lake, Southern California, Sedimentary Geology, in press.
2009 Bird, B.W., Kirby, M.E., Howat, I., and Tulaczyk, S., Geophysical Evidence for Holocene Lake-Level Change in Southern California (Dry Lake), Boreas, in press.
2007 Kirby, M.E., Students Look to the Past to See the Future, National Ground Water Association, Groundwater: News and Views (invited commentary), Volume 4, Number 1, June, p. 7-8.
2007 Kirby, M.E., Lund, S.P., Anderson, M.A., Bird, B.W., Insolation Forcing of Holocene Climate Change in Southern California: A Sediment Study From Lake Elsinore, Journal of Paleolimnology, 38, p. 395-417 doi: 10.1007/s10933-006-9085-7.
2006 Kirby, M.E., Lund, S.L., and Bird, B.W., Mid-Wisconsin Sediment Record From Baldwin Lake Reveals Hemispheric Climate Dynamics (Southern CA, USA), Palaeogeography, Palaeoclimatology, Palaeoecology, 241, p. 267-283, doi: 10.1016/j.palaeo.2006.03.043.
2006 Bird, B.W. and Kirby, M.E., An alpine lacustrine record of early Holocene North American Monsoon dynamics from Dry Lake, southern California (USA), Journal of Paleolimnology, 35, p. 179-192.
2005 Kirby, M.E., Lund, S.P., Poulsen, C.J., Hydrologic variability and the onset of modern El Niño-Southern Oscillation: a 19,250-year record from Lake Elsinore, Southern California, Journal of Quaternary Science, 20, p. 239-254.
2005 Kirby, M.E., Determination of Sedimentation Rate and Sedimentation Processes at Big Bear Lake: Using a Paleo-Perspective to Understand Modern Sedimentary Systems, Final Report submitted to Big Bear Municipal Water District, 41pp.
2005 Kirby, M.E., Anderson, M., Lund, S.P., and Poulsen, C.J., Developing a baseline of natural lake-level/hydrologic variability and understanding past versus present lake productivity over the late-Holocene: a paleo-perspective for management of modern Lake Elsinore, Final Report submitted to Lake Elsinore-San Jacinto Water Authority, 79pp.
2004 Kirby, M.E., Poulsen, C.J., Lund, S.P., Patterson, W.P., Reidy, L., and Hammond, D.E., Late Holocene lake level dynamics inferred from magnetic susceptibility and stable oxygen isotope data: Lake Elsinore, Southern California (USA), Journal of Paleolimnology, 31, p. 275-293.
2003 Byrne, R., Reidy, L., Kirby, M., Lund, S., and Poulsen, C., Changing Sedimentation rates during the Last Three Centuries at Lake Elsinore, Riverside County, California, Final Report to the Santa Ana Regional Water Quality Control Board, 41pp.
Affiliation: Scripps Institution of Oceanography, U.C. San Diego
Ecosystem-level consequences of decreasing dissolved oxygen and pH of the Eastern Pacific Margin - Quantifying natural variability of coastal ocean carbonate chemistry and implications for invertebrate early life stages - Sea level rise planning for the Kendall Frost/Northern Wildlife Preserve: A class project
1. Lead PIs: L.A. Levin (SIO), Jaime Färber (CICESE) Co-PIs: J.M. Hernandez-Ayon (UABC), F. Delgadillo-Hinojosa (UABC), C. Neira (SIO) Collaborators: V. Diaz (CICESE), A. Dickson (SIO), T. Martz (SIO), J.Helly (SIO), S. Bograd (NOAA-SFSC), C. Tanner (Grad Student, SIO).
Title: Declining Oxygenation and pH of the Eastern Pacific Margin: Evaluating Trends and Ecosystem-Level Consequences for California and Mexico, UC Mexus (award # 19900R)
Statement of Problem: Global warming can lead to oxygen declines because (1) warming increases stratification which reduces mixing, (2) warmer water holds less oxygen, (3) warmer temperatures raise the respiration rates of organisms, thereby consuming oxygen. Oxygen in the open ocean is declining globally and in the tropical and subtropical oceans. Oxygen minimum zones are expanding; declines of > 20% have been observed at depths of 100-600 m in the N.E. Pacific and at depths of 200-300 m off southern California. The hypoxic zone (< 1.4 ml/l) has shoaled by as much as 100 m off southern California and now impinges periodically on the outer shelf. Similar changes in oxygenation are likely to have occurred off Mexico with considerable variability.
Intrinsically connected to dissolved oxygen is the pH of seawater; the respiration activities that deplete oxygen also release CO2, which in turn, lowers pH, i.e., leading to ocean acidification. As CO2 dissolves in seawater, more carbonic acid is produced which is corrosive to the shells and skeletons of many marine organisms, including calcareous plankton, corals, molluscs, and fish otoliths. Other fundamental processes that can be affected by pH changes are decomposition, photosynthesis, N cycling, etc. All these changes resulting from climate change will be manifested in shifts in species distributions, algal and faunal composition, and potentially in local extinctions.
Objectives: This research program develops an eastern Pacific oxygen monitoring network to interpret past, present and future changes in ocean oxygen and pH data off California and Mexico, and to assess and understand the ecosystem-level consequences of hypoxia and low pH. This project, initiated through interaction between California and Mexico via UC Mexus funding, attempts to eventually expand the monitoring network to include scientists and data from Canada, Washington, Oregon, Equador, Peru and Chile. We expect to establish outreach (education, science diffusion) to the local communities focused on the ecological significance of oxygen, pH and OMZs in the coastal ocean, their role in determining resource distribution and their links to anthropogenic disturbances (eutrophication, global warming, CO2 fertilization).
Outcome: Establishment of a monitoring network and results from this research will contribute to improved regional predictions of changes in fisheries resources generated by climate-induced fluctuations in the OMZ. It will strengthen the capacity of coastal zone and fisheries regulators in each country to respond to temporal variability in oxygenation of near shore waters in a way that promotes sustainable development. The information produced will be made readily available and usable by policymakers attempting to formulate effective strategies to undertake future scientific assessments with the ultimately goal of prevent, mitigate, and adapt to the effects of global change.
2. Christina Tanner, SIO Graduate Student (Levin)
Title: Variability in coastal ocean pH and consequences for invertebrate larvae
Statement of Problem: Increased concentrations of atmospheric carbon dioxide are acidifying the marine environment at unprecedented rates. By the year 2100 pH is anticipated to decrease by 0.3-0.4 units. pH in the open ocean, while declining, is fairly constant on short time scales. However, in the coastal zone, extreme variability in carbonate chemistry is driven by fluctuations in temperature, salinity, air-sea gas exchange, mixing processes, and biological activities. This variability is magnified in kelp forests, an ecosystem that supports California’s coastal communities through recreation, fisheries, and intrinsic aesthetic and ecological value. Kelp forests consume and release significant amounts of dissolved inorganic carbon (DIC) on daily to seasonal scales, altering pH by up to 1 unit in a day. Understanding and predicting the interaction of marine species with ocean acidification requires knowledge of how species respond to natural variation.
Approach: The objectives of this study are to (a) develop statistical tools to characterize pH variability in the coastal zone, specifically within and outside kelp forests, (b) identify pH levels, variability regimes and thresholds that affect invertebrate larvae, and (c) produce a comparative assessment of the range in sensitivities of larval forms tested. Carbonate chemistry monitoring efforts will be localized inside and outside kelp forests in San Diego in order to develop and employ statistical characterization of carbonate chemistry variability. The ensuing metrics will be incorporated into a series of laboratory experiments to test how various pH regimes affect larval survivorship, growth, and calcification processes. These experiments are designed to test the hypotheses that (1) Kelp forests induce variability in carbonate chemistry in a predictable spatial and temporal context corresponding to cycles of primary production and community respiration. (2) Planktonic invertebrate larval health is sensitive to decreased pH, but negative effects are ameliorated when incorporating variable pH. (3) Larval responses to pH regimes are correlated with larval developmental mode (planktotrophs are more sensitive) and with the presence of calcified structures (calcifiers are more sensitive), but some larval forms are pre-adapted to cope with declining pH.
3. Class project for SIO 286 – Wetlands Ecology, Conservation and Management (Spring 2009)
Title: Sea Level Rise Planning for the Kendall Frost/Northern Wildlife Preserve
Because coastal wetlands develop at the interface of land and sea, and are strongly regulated by seawater inundation, sea level rise (SLR) is a strong force for wetland change. The class project will involve prediction and planning for sea level rise effects at the UCSD/City of San Diego-owned wetland reserve in Mission Bay. The class will break into groups to address a diversity of issues associated with sea level rise in southern California wetlands. A final written report will be prepared which includes evaluation on the expected amount of SLR, SLR effects on soil parameters, erosion and accretion associated with SLR, effects on habitat, animals, and species interactions, as well as solutions, coastal property rights, interactions with development, and future directions. Presentations will be made in class during the final exam period, and in May to the San Diego Wetlands Advisory Board. The class also will create a template that can be used broadly by other regional wetland managers for evaluating sea level rise effects in southern California.
Affiliation: Integrative Oceanography Division, Scripps Institute of Oceanography, U.C. San Diego
- Population ecology of marine zooplankton (especially planktonic copepods)
- Zooplankton predator-prey interactions
- Autonomous measurement methods (Spray ocean gliders, moorings)
- Climate change effects on California Current pelagic food webs
The California Current Ecosystem (CCE) Long Term Ecological Research (LTER) site: “Nonlinear transitions in the California Current Coastal Pelagic Ecosystem” – A group of more than 25 biological, physical, chemical oceanographers and climate scientists is investigating the mechanisms leading to temporal variations in the pelagic ecosystem of the California Current. We seek to develop a specific mechanistic understanding of the processes underlying low-frequency ecosystem transitions that have been characterized by the CalCOFI program over more than 60 years. This is done via experimental process cruises; time-series observations using ocean gliders, shipboard surveys, and satellite remote sensing; and coupled biophysical models. Numerous graduate students are actively involved in the CCE-LTER research site.
Aksnes, D. L., and M. D. Ohman, Multi-decadal shoaling of the euphotic zone in the southern sector of the California Current System. Limnology and Oceanography, in press, 2009.
Landry, M. R., M. D. Ohman, R. Goericke, M. R. Stukel, and K. Tsyrklevitch, Lagrangian studies of phytoplankton growth and grazing relationships in a coastal upwelling ecosystem off Southern California. ICES Journal of Marine Science, in press, 2009.
Davis, R. E., M. D. Ohman, B. Hodges, D. L. Rudnick, and J. T. Sherman, Glider surveillance of physics and biology in the southern California Current System. Limnology and Oceanography, 53 (5, part 2), 2151-2168, 2008.
Ohman, M. D., and C. -H. Hsieh, Spatial differences in mortality of Calanus pacificus within the California Current System. Journal of Plankton Research, 30, 359-366, 2008.
Lavaniegos, B. E., and M. D. Ohman, Coherence of long-term variations of zooplankton in two sectors of the California Current System. Progress in Oceanography, 75 (1), 42-69 (+ electronic supplement), 2007. DOI 10.1016/j.pocean.2007.07.002.
Aksnes, D. L., M. Ohman, and P. Rivière, Optical effect on the nitracline in a coastal upwelling area. Limnology and Oceanography, 52 (3), 1179-1187, 2007.
Sydeman, W. J., R. W. Bradley, P. Warzybok, C. L. Abraham, J. Jahncke, K. D. Hyrenbach, V. Kousky, J. M. Hipfner, and M. D. Ohman, Planktivorous Auklet Ptychoramphus aleuticus Responses to Ocean Climate, 2005: Unusual Atmospheric Blocking?. Geophysical Research Letters, 33 (22), L22S09, 2006.
Field, D. B., T. R. Baumgartner, C. D. Charles, V. Ferreira-Bartrina, and M. D. Ohman, Planktonic foraminifera of the California Current reflect twentieth century warming. Science, 311 (5757), 63-66, 2006.
Hereu, C. M., B. E. Lavaniegos, G. Gaxiola-Castro, and M. D. Ohman, Composition and potential grazing impact of salp assemblages off Baja California during the 1997-1999 El Niño and La Niña. Marine Ecology Progress Series, 318, 123-140, 2006.
Hsieh, C. H., and M. D. Ohman, Biological responses to environmental forcing: The Linear Tracking Window hypothesis. Ecology, 87 (8), 1932-1938, 2006.
Ohman, M. D., and E. L. Venrick, CalCOFI in a changing ocean. Oceanography 16: 76-85, 2003.
Rau, G. H., M. D. Ohman, and A. C. Pierrot-Bults, Linking nitrogen dynamics to climate variability off Central California: A 51 year record based on 15N/14N in CalCOFI zooplankton. Deep-Sea Research II 50: 2451-2467, 2003.
Affiliation: Department of Biology, U.C. Riverside
- Detecting present-day shifts in species distributions based on comparison of current surveys with historical data
- Examining predictions of future distributions of species based on coupling climate models to species' niche models.
Hargrove, L., and J.T. Rotenberry. In press. Elevational shifts in breeding bird distributions over a 26-year period in a southern California desert region. In T.L. Root, K.R. Hall, M. Herzog, and C. A. Howell (editors). Biological Impacts of Climate Change in California: Case Studies Linking Science and Management. California Energy Commission Public Interest Energy Research, Sacramento, CA.
Preston, K.L., J.T. Rotenberry., R.A. Redak., and M.F. Allen. 2008. Habitat shifts of endangered species under altered climate conditions: importance of biotic interactions. Global Change Biology 14:2501-2515. DOI 10.1111/j.1365-2486.2008.01671.x
Affiliation: Department of Botany and Plant Sciences, U.C. Riverside
- Studying the relative vulnerability of desert chaparral species to climate change-type drought and how their physiological responses to water availability is likely to affect ecosystem-level water cycling.
- Studying nutrient limitation of photosynthesis and productivity in tropical forest to understand how changes in nutrient regime will mitigate the effects of changing CO2 concentrations on productivity.
Cornwell WK, Cornelissen JHC, Amatangelo K, Dorrepaal E, Eviner VT, Godoy O, Hobbie SE, Hoorens B, Kurokawa H, Perez-Harguindeguy N, Quested HM, Santiago LS, Wardle DA, Wright IJ, Aerts R, Allison S, Bodegom Pv, Brovkin V, Chatain A, Callaghan T, Díaz S, Garnier E, Gurvich DE, Kazakou E, Klein JA, Read J, Reich PB, Soudzilovskaia NA, Vaieretti MV, Westoby M. 2008. Plant species traits are the predominant control on litter decomposition rates within biomes worldwide. Ecology Letters 11:1065-1071
Santiago LS (2007) Extending the leaf economics spectrum to
decomposition: Evidence from a tropical forest. Ecology 88:1126-1131
Affiliation: Department of Environmental Sciences, U.C. Riverside
- Effects of warming on permafrost carbon balance
- Implications of changing snow regimes on nitrogen cycling
Schuur, E., Vogel, J.G., Crummer, K., Lee, H., Sickman, J.O., Osterkamp, T.E. In Press. Permafrost thaw stimulates old carbon release and alters net carbon exchange from upland tundra. Nature.
Sickman, J.O., Leydecker, A., Chang, C.C., Kendall, C., Melack, J.M., Lucero, D.M., Schimel, J.P. 2003. Mechanisms underlying export of N from high-elevation catchments during seasonal transitions. Biogeochemistry. Vol. 64: p.1-32.
Affiliation: Department of Earth System Science, UC Irvine
- Efffects of pollution on snow reflectance and melt
- Distribution of offshore windpower
- Snow Process Studies and Modeling to Improve Arctic Climate Prediction
- Black Carbon Impacts on Cryospheric Climate Sensitivity and Surface Hydrology
- Fire at the Intersection of Global Carbon and Water Cycles
Capps, S. B., and C. S. Zender (2009), Global Ocean Wind Power Sensitivity to Surface Layer Stability, Geophys. Res. Lett., 36, L09801, doi:10.1029/2008GL037063.
Flanner, M. G., C. S. Zender, P. G. Hess, N. M. Mahowald, T. H. Painter, V. Ramanathan, and P. J. Rasch (2008), Springtime Warming and Reduced Snow Cover from Carbonaceous Particles, Atmos. Chem. Phys., 9(7), 2481-2497.
McConnell, J. R., P. R. Edwards, G. L. Kok, M. G. Flanner, C. S. Zender, E. S. Saltzman, J. R. Banta, D. R. Pasteris, M. M. Carter, and J. D. W. Kahl (2007), 20th-Century Industrial Black Carbon Emissions Altered Arctic Climate Forcing, Science, 317(5843), 1381-1384, doi:10.1126/science.1144856.